Those of you who have ridden with us for more than a year likely know by now that when the weather starts to turn cold and cloudy, it can impact our solar-powered stations, which total 26 of our 43 active stations. However, this year the problem has presented itself earlier and far more aggressively than anticipated. Of course, you don’t need us to tell you how bad it’s been—you’ve likely been personally impacted by these issues over the last week:

The purpose of this post is to explain what we know about the cause of the issues, as well as what we’re doing to fix them, including possible changes we’re looking to make in our operations going forward.

First, here’s what we know about solar issues: each solar station houses two twelve volt batteries, which are intended to be charged by the solar panel over the course of the day. Absent any solar power, we expect those batteries to last approximately 48 hours. While the current string of overcast weather we’re seeing—nearly a week without prolonged direct sun—is certainly rare for Boulder, increased system use is also placing extra demand on solar-powered stations, as Boulder B-cycle riders are on track to take 100,000+ trips in 2017!

Typically, we’re able to stay ahead of solar issues by adjusting solar panels and charging a bank of batteries in our office to swap into stations as they run low on power, though there are limitations based on the power supply of our non-industrial office/shop space. Even though we’ve recently invested in fresh batteries and a larger charging bank, our capacity to charge only eight batteries at a time leaves us unable to fully respond to the scale of issues we’re currently seeing.

Based on the outcomes of pending conversations with our equipment provider and other bike sharing programs around the country, we’re also exploring the possibility of investing in some longer-term solutions, which could include some combination of the following:

Replacing some of our current stock of batteries with high-capacity, fast-charging lithium iron phosphate (LiFePo) batteries

Locating an offsite space where we can operate more battery charging points simultaneously

Sourcing higher-efficiency solar panels or upgrading solar power controllers to better draw power in overcast conditions

As always, we’re working to run the best bike sharing program possible with the resources that are available to us. To that end, we have found ourselves unable to provide a satisfactory level of service this past week, and we apologize for the inconvenience that we know this has caused.